Some folks say yes, some folks say no. I recommend that you stay on the conservative side, work with the slower powders and you should stay out of trouble. You'll probably hear from all the "experts", but I've banged out quite a few factory loads and factory level reloads on my contender and the only thing worse for the wear was my hands and nerves.
Rumors are that at one website who shall not be named here...that he has fired several thousand rounds of full house 444s with no damage or stretching to the frame.
regards, good luck,
Graycg